I just noticed, at the beginning when Little Jerry sings "Danger", his hair is slicked back (you can see his ears), but once the song starts, it becomes his trademark shaggy mop.

Maybe between singing gigs, he had to hold down a straight job to pay the bills. In the mid-70's, the economy wasn't so good.
Imagine walking into a burger joint and seeing our hero behind the counter." You want fries with that?"

But back then, a pukeburger, fries, and drink would set you back $1.50.